Extendable shelf rail



FIG. 1 is a front, top, left perspective view of an extendable shelf rail showing the new design;

FIG. 2 is a front elevation thereof;

FIG. 3 is a left side elevation thereof;

FIG. 4 is a right side elevation thereof;

FIG. 5 is a top plan thereof; and,

FIG. 6 is a bottom plan thereof. 

CLAIM The ornamental design for an extendable shelf rail, as shown and described. 